Patent GB-891771-A (GB)
Title: Preparation of n-aralkyl amides
IPC: C07C233/00
Filed: 1958-10-17
Abstract: Polyamides may be prepared from polyamines of the formula Ar(CH2NH2),n where n=1-3 and Ar is a mononuclear aryl radical substituted by alkyl or alkoxy groups or a polynuclear aryl radical which may be substituted by alkyl or alkoxy groups and dicarboxylic acids, e.g. sebacic or adipic acid. The preferred amine is 4,6-bis(aminomethyl)-m-xylene.  The amines may also be used as hardening agents in the curing of epoxy resins.  Polyurethanes may be prepared from diisocyanates of the formula Ar(CH2NCO)2, where Ar is a mononuclear aryl radical substituted by alkyl or alkoxy groups or a polynuclear aryl radical which may be substituted by alkyl or alkoxy groups, and aliphatic polyols such as castor oil or mixtures thereof with polyethylene glycol or saturated polyesters containing free hydroxy groups.  The preferred isocyanate is 4,6-bis(isocyanatomethyl)-m-xylene. 4,6-bis-(acrylamidomethyl-m-xylene is homopolymerized by heating, e.g. above 200 DEG C.ALSO:A method for the preparation of an N-aralkyl amide of the formula Ar(CH2NHCOR)n where Ar is a mononuclear aryl radical substituted by alkyl or alkoxy groups or a polynuclear aryl radical which may be substituted by alkyl or alkoxy groups, n is 1, 2 or 3 and R is a radical which does not enter into the principal reaction comprises reacting (1) an aromatic compound of the formula Ar(H)n with an amide of the formula RCONHCH2Y, where Y is a polar group, (2) an aromatic compound of the formula Ar(H)n with an amide of the formula RCONH2 in combination with formaldehyde or a source thereof, (3) an aromatic compound of the formula Ar(H)n with a nitrile of the formula RCN in combination with formaldehyde or a source thereof, or (4) an aromatic compound of the formula Ar(CH2OH)n with a nitrile of the formula RCN, Ar having at least one alkyl or alkoxy substituent in the ortho or para position to any methylol group converted to amidomethyl; the reactions being conducted in the presence of an acid catalyst. The catalyst may be sulphuric or phosphoric acid, a sulphonic acid such as toluene sulphonic acid or a Lewis acid such as zinc p  chloride or boron trichloride etherate.  A preferred catalyst is 10%-90% sulphuric acid dissolved in glacial acetic acid and is employed in an amount of 20% to 80% based on the total reactants. The reaction using an aromatic methylol compound is preferably carried out using at least one mole of nitrile for each methylol group to be converted to amidomethyl, a solvent is generally not used.  The reaction using Ar(H)n and RCN preferably takes place by adding formaldehyde (or paraformaldehyde or trioxymethylene) to the nitrile and catalyst and finally adding the aromatic compound although other procedures may be used.  The proportions of reactants may vary in accordance with the product desired, a large excess of the aromatic compound being used when a mono-amide is required.  The reaction of the aromatic compound with an amide takes place under similar conditions, saturated and unsaturated amides, aromatic amides, diamides of dibasic acids, ureas and alkyl carbonates may be used.  N-substituted amides may be used in place of amides, in which case a methylene supplying agent is not required.  The N-substituent being CH2Y where Y may be a polar group such as Cl, OH, OR1, OCH2 NHCOR1, OCOR, or -NHCOR, where R1 may be the same as R or different. The amides may be converted by known methods into the corresponding amines which may be further reacted, e.g. to isocyanates.  The examples describe reactions between (1) 4,6-bis-hydroxymethyl-m-xylene and nitriles to give products where R is methyl, vinyl and methyl-vinyl, when acetonitrile is used 4-acetamidomethyl-6-acetoxymethyl-m-xylene may also be obtained; (2) o-, m-, p-xylenes, toluene, naphthalene and durene with nitriles in the presence of formaldehyde to give products where n is 1 or 2 and R is H, methyl or vinyl, (3) m-xylene with amides in the presence of formaldehyde to give products where n=2 and R is methyl or vinyl and (4) m-xylene with N-substituted amides to give products where R is methyl or vinyl and n is 1 or 2.  4,6-bis-(isocyanatomethyl)-m-xylene is obtained by treating 4,6-bis (aminomethyl)-m-xylene dihydrochloride with phosgene.  4,6-bis (aminomethyl)-m-xylene is obtained by hydrolysing 4,6-bis (acetamidomethyl)-m-xylene with sulphuric or hydrochloric acid.  6-acetoxymethyl-m-xylene is obtained together with N-(2,4-dimethylbenzyl)-acetamide when 2,4-dimethylbenzyl alcohol is treated with acetonitrile.  4,6 - bis (chloroacetamido) - m - xylene, 4,6 - bis (chloropropionamidomethyl) - m - xylene and 4,6-bis (benzamidomethyl)-m-xylene may be obtained by treating 4,6-bis-(hydroxymethyl)-m-xylene with chloroacetonitrile, chloropropionitrile and benzonitrile respectively. Di-acetamidomethyl ether is obtained by refluxing a mixture of acetamide and paraldehyde in xylene.  N-acetoxymethyl acetamide is obtained by heating a mixture of acetamide and paraldehyde and pouring the product into a 1 : 1 mixture of acetic acid and acetic anhydride.  N,N1-methylene bis-acetamide is obtained by treating 1 mole of paraldehyde with 2 moles of acetamide.